There are increasing numbers of applications for articles coated with thin films of organic coatings. For example, an economically produced thin film coating having particular properties can be used in food packaging or as a protective coating for metal or other substrates used in information display, medicine, instrumentation. While coating systems are available in the art, unfortunately, systems presently available operate at speeds which are too slow to be economically justified or the coating produced is not satisfactory for the particular substrate to be coated or the environment in which the substrate exists.
Illustrative of such systems is a coating process disclosed in British patent specification No. 1,168,641 published Oct. 29, 1969. That process involves coating substrates by vaporizing a reactive material which is deposited (under vacuum) on the surface of a substrate. The coated substrate is then exposed to electron beam, X-rays, or gamma rays in order to cross-link or cure the deposited material. The British reference discloses a number of polymers and monomers which can be employed as reactive materials, including monomeric acrylates having a single, reactive double bond. The rate of deposition of curable materials, however, is not satisfactory for many applications; the deposition rate being disclosed as one micron/second with the curing being accomplished in times varying from one second to one minute.
It is an object of the present invention to provide a thin film coating which can be produced relatively economically and at a relatively high speed of production.
It is further an object of the present invention to provide a coating structure that has mechanical and electrical properties which are useful in a variety of coating applications.